The present invention relates to packaging and, in particular to the manufacture of slider zipper packaging on a horizontal form, fill and seal (FFS) machine.
Packaging with zippers has become increasingly popular as the primary packaging for a wide variety of goods, and, in particular for food products. Such zippers may be operated simply by pressing the profiles together or pulling them apart to close and open the zipper or by moving a slider along the zipper profiles to engage and disengage the zipper profiles. Slider activated zippers are becoming increasingly popular for primary packaging, perhaps because they impart to the consumer the perception of a more securely closed package and ease of operation. The addition of a slider to the zipper package makes it more difficult to assemble the package particularly if relatively high speed, automated equipment is to be used to form, fill and seal the package as is quite common in the food industry.
The present invention provides a method of forming, filling and sealing a reclosable package with a slider activated zipper. The method comprises moving a base film longitudinally (i.e. in the running direction of the film) to a filling station and, in a moving direction, away from said filling station. At the filling station a product is fed onto the base film. As the base film carrying product is moved from the filling station, a zipper with a slider attached thereto is fed onto the moving film in the moving direction of the base film. The zipper has a first profile and a second profile, each of which has a web attached thereto extending away from the slider. A top film is then applied over the base film and the first profile web is sealed to the base film and the second profile web is sealed to the top film. The package is completed by cross-sealing the base film and the top film together on opposite sides of the product, capturing said product between adjacent cross seals and transversely cutting the sealed together base film and top film.
The top and base films may be formed from the same sheet in which case the package top or bottom or one side would be formed as a longitudinal fold line that separates the top and bottom films. Alternatively, the top and bottom films may be separate films in which case a bottom seal would have to be formed opposite the zipper joining the top and base films together. If separate films, the base film may be a thermoform film which can be formed into adjacent product receptacles.
The slider is attached to the zipper as the zipper moves to the base film. To this end, as the zipper moves to the film, the zipper is stomped or shaped at bag length intervals to retain the slider on the zipper and a slider is attached to the zipper between adjacent stompings. After the zipper is attached to the base film the profiles are further stomped or shaped to aid in allowing the package to make a hermetic seal.